Castable infrared illuminant compositions

Abstract

Compositions are provided which, when burned, produce significant levels of infrared radiation, but only limited levels of visible radiation. The basic components of the compositions include a binder, an oxidizer, and a fuel, where the binder also acts the fuel. Preferred oxidizers include those compounds which produce large quantities of infrared radiation when the flare composition is burned. Such oxidizers include potassium nitrate, cesium nitrate, rubidium nitrate, and combinations of these compounds. Selection of the binder is important in order to provide the composition with the desirable characteristics identified above. The binder of the present invention does not produce significant soot. At the same time, the binder serves to form a composition which is processible, avoids chunking, and is compatible with the oxidizers used. It has been found that polymer binders which include relatively short carbon chains (1-6 continuous carbon atoms) are preferred. Examples of such polymers include polyesters, polyethers, polyamides, and polyamines.

Description

1. The Field of the InventionThe present invention is related to illuminant compositions which emit significant quantities of infrared radiation. More particularly, the present invention is related to castable infrared illuminant compositions which exhibit high initial burn rates, burn cleanly, and emit relatively small quantities of visible light in proportion to the infrared radiation emitted.2. Technical BackgroundThere is a need in various situations for an ability to see clearly at night, or during periods of substantially reduced sunlight. Such situations may, for example, include search and rescue operations, police surveillance, and military operations. In these types of situations, it is often important that key personnel have the ability to see clearly, even though there is limited sunlight.In order to solve the problem of visibility at night, or during periods of substantially reduced sunlight, devices have been developed which allow one to see based upon available infrar...

AI Technical Summary

Benefits of technology

The present invention is related to novel and inventive compositions which produce significant quantities of infrared radiation when burned. At the same time, the compositions avoid many of the limitations of the existing art. The compositions have high burn rates, produce relatively little visible light in proportion to infrared radiation produced (in that they substantially avoid soot formation). The compositions also avoid common problems such as chunking and poor high temperature aging. Finally, the compositions are castable. That is, the compositions are capable of being poured in liquid form into a mold, then taking the shape of the mold without the application of excessive pressure.

Compositions within the scope of the present invention also age and store well. This is a further feature which has not generally been available in known compositions. Compositions within the scope of the present invention may be stored at elevated temperatures (for example, 135.degree. F.) for up to a year without significant degradation.

Problems solved by technology

This severely limits the fuels that can be used.

Hydrocarbon fuels have been evaluated and many tend to produce soot, which can lead to high visible light output.

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